A graph of position versus time for a certain particle moving along the x-axis is shown in Figure P2.6. Find
the instantaneous velocity at the instants (a) t 5 1.00 s,
(b) t 5 3.00 s, (c) t 5 4.50 s, and (d) t 5 7.50 s.

Arefrigerator uses r-134a as the working fluid and operates on the ideal vapor-compression refrigeration cycle except for the compression process. the refrigerant enters the evaporator at 120 kpa with a quality of 34 percent and leaves the compressor at 70°c. if the compressor consumes 450 w of power, determine (a) the mass flow rate of the refrigerant, (b) the condenser pressure, and (c) the cop of the refrigerator. (0.00644 kg/s, 800 kpa, 2.03)